Comparison of 12-core prostate biopsy results with corresponding radical prostatectomy specimens

IntroductionA standard biopsy strategy in terms of describing the ideal number of biopsy cores and localization has not been formulated. The objective of this current study was to compare the histological findings of 12-core transrectal ultrasound (TRUS) guided prostate biopsy results with that of corresponding radical prostatectomy specimens.Material and MethodsThis retrospective trial consisted of 52 consecutive patients who underwent radical prostatectomy between January 2005 and October 2009 at our institution. All patients had 12-core prostate biopsy (lateral and far lateral biopsies from apical, mid and basal prostate tissue for each half of the prostate as a total of 12 locations in each case) that was performed by a single physician.The diagnostic ability of biopsy cores, cancer locations and the histological findings particularly Gleason grades of 12-core biopsies were compared with that of radical prostatectomy specimens.ResultsThe classical sextant biopsy revealed prostate cancer in 71% (37/52) of cases. About 29% (15/52) of cancers were detected only by the far lateral sextant biopsies. The diagnostic ability of 12-core biopsies was statistically higher than the classical sextant approach.A total of 35 patients were found to have unilateral cancer according to TRUS biopsies. However about 71% of these cases was bilateral disease on radical prostatectomy specimens. Gleason scores of TRUS biopsies were intermediate, intermediate-poor and poorly differentiated in 63.5%, 32.7% and 3.8% of cases, respectively. These scores were well correlated with corresponding radical prostatectomy Gleason scores.ConclusionsThe addition of far lateral biopsies to the classical sextant biopsy revealed a significant improvement in cancer detection rate. Unilateral disease on biopsy was mostly associated with bilateral cancer on corresponding radical prostatectomy specimen. Gleason score on TRUS biopsy was usually correlated with a corresponding Gleason score on final pathology.